I empirically analyze how changes in access to housing collateral affect homeowner borrowing behavior. To isolate the role of collateral constraints from that of wealth effects, I exploit the fully-anticipated expiration of resale price controls on owner-occupied housing in Montgomery County, Maryland. I estimate a marginal propensity to borrow out of housing collateral that ranges between $0.04–$0.13 and is correlated with homeowners’ initial leverage. Additional analysis of residential investment and ex-post loan performance indicates that some of the extracted funds generated new expenditures. These results suggest a potentially important role for collateral constraints in driving household expenditures.